The present invention relates to apparatus for controlling lint and dust in workplaces, for example, textile plants, and relates more specifically to an apparatus particularly adapted for collecting airborne lint from a work area and for limiting lint accumulation on overhead surfaces thereabove.
At substantially all stages of the processing of textile fibers, particularly cotton, from the initial fiber cleaning and preparation stage through yarn spinning and fabric production, the necessary handling of the textile fibers and yarns inherently liberates minute pieces of fiber, commonly referred to as lint, as well as other particulate dust and debris which tend to become readily airborne within the work area of the textile processing plant and ultimately to settle and accumulate on machinery and other exposed surfaces within the plant interior. Lint, dust and other such debris pose a variety of problems to the textile manufacturer. First, workers are continuously subjected to the inhalation of airborne lint and the like which, at concentration levels often produced in textile cotton processing plants, poses a potential hazard that workers may develop respiratory problems, such as "brown lung" disease, as a result of extended exposure. Secondly, in yarn spinning and fabric production operations, airborne lint and dust which settle on the processing machinery or yarn being processed or utilized may cause machine stoppages as well as defects in the yarn or fabric produced, which utlimately adversely affects operating efficiency and revenues. Finally, apart from the foregoing problems, textile plants which generate lint and other debris require periodic cleaning of accumulations thereof from processing machinery as well as virtually all exposed interior plant surfaces, which generally is a labor-intensive and therefore relatively expensive matter.
Conventional attempts to control airborne lint and lint accumulation have been directed, to a large extent, to the filtration of lint-laden air, for example, by continuously withdrawing and filtering the lint-laden air from the workplace and replacing it with clean filtered or outside air. However, lint filtration is effective only to the extent of reducing to varying degrees the concentration of airborne lint and the rate of lint accumulation. In practice, it is extremely difficult to control the conveyance of airborne lint by a moving air flow in a relatively open environment such as a textile processing plant due to the minute size and light weight nature of lint which makes it highly reactive to air turbulence. As a result, relatively high filtration air flow rates are necessary to entrain and transport any significant proportion of airborne lint in typical textile mill work environments, which generally is impractical. Accordingly, typical centralized lint filtration systems in textile plants generally do not extract a high proportion of airborne lint and like debris.
One conventional alternative to a centralized filtration system for an entire textile plant is to provide individual filter modules strategically located at a number of locations throughout the plant to attempt to collect airborne lint and debris close to the location of lint generation. An example of this type of so-called modular filtration system is manufactured by ModuFil, Inc., of Knoxville, Tenn., under the model designation "Lint Trap 5000." Each filter module basically comprises a free-standing cylindrical filter with a fan coaxially mounted interiorly between a lower filter section and an upper exhaust section. The fan draws ambient lint-laden air radially inwardly through the circumference of the filter section and returns the filtered air radially outwardly through the circumference of the exhaust section. While this filter apparatus is reasonably effective for lint control within a localized work area, the radially inward and outward air circulation created by the apparatus limits its effectiveness to only the ambient area laterally adjacent the apparatus with essentially no effect on airborne and accumulated lint within elevated areas of the workplace overhead.